Bioactive Silk Revolution: Harnessing Curcuminoid Dye and Chitosan for Superior Antimicrobial Defence and UV Shielding.

BACKGROUND/

OBJECTIVES

The use of natural colourants is gaining attention due to their biocompatibility and functional benefits. This study introduces a different approach using turmeric (Curcuma longa L.) dye extract combined with chitosan to significantly enhance the antibacterial and UV-shielding properties of silk.

METHODS

The turmeric dye's chemical composition was analyzed using liquid chromatography mass spectrometry (LC-MS), UV-visible spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). The dyed silk's colourfastness was tested through rubbing, washing, and light exposure.

RESULTS

The chitosan-mordanted silk showed strong antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as antifungal activity against Aspergillus niger (A. niger). It also demonstrated a high ultraviolet protection factor (UPF). For comparison, alum-mordant was used, and chitosan proved more effective. Beyond its use as a dye, turmeric is renowned for its medicinal properties. Its antioxidant, anticancer, and anti-inflammatory properties have been extensively researched, which are primarily linked to its curcuminoid compounds. Turmeric is used in traditional medication to treat digestive issues, arthritis, and skin diseases.

CONCLUSIONS

This work underscores the innovative use of plant-based dye extracts and natural mordants like chitosan as a sustainable alternative to conventional metallic mordants, paving the way for the evolution of bioactive silk with improved functional properties.